Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net income (loss)	$ 7.0	$ 49.2
Preferred stock dividends	2.6	2.6
Net income (loss) applicable to common shareowners - basic and diluted	$ 4.4	$ 46.6
Denominator:
Weighted average common shares outstanding - basic	210.0	209.2
Stock-based compensation arrangements	0.4	0.0
Weighted average common shares outstanding - diluted	210.4	209.2
Income (Loss) from Continuing Operations, Per Basic and Diluted Share	$ 0.02	$ (0.01)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic and Diluted Share	0.00	0.23
Earnings Per Share, Basic and Diluted	$ 0.02	$ 0.22
Continuing Operations [Member]
Numerator:
Net income (loss)	$ 7.0	$ 0.3
Preferred stock dividends	2.6	2.6
Net income (loss) applicable to common shareowners - basic and diluted	$ 4.4	$ (2.3)
Denominator:
Weighted average common shares outstanding - basic	210.0	209.2
Stock-based compensation arrangements	0.4	0.0
Weighted average common shares outstanding - diluted	210.4	209.2
Discontinued Operations [Member]
Numerator:
Net income (loss)	$ 0.0	$ 48.9
Preferred stock dividends	0.0	0.0
Net income (loss) applicable to common shareowners - basic and diluted	$ 0.0	$ 48.9
Denominator:
Weighted average common shares outstanding - basic	210.0	209.2
Stock-based compensation arrangements	0.4	0.0
Weighted average common shares outstanding - diluted	210.4	209.2
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3.0
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4.5	4.5